For parents who hover, a playground can look like a very dangerous place for their kids. But medical experts warn that parental efforts to keep their young children safe often backfire -- and end up harming them instead.

Nora Abularach of New York keeps her impulses in check. On Wednesday she watched as her 2-year-old son, Sam, scurried up the ladder to a big yellow slide at a Central Park playground. Abularach remained a few feet away near the foot of the slide. Sam paused at the top for a moment, looking to his mom for reassurance. A few encouraging words later, Sam was zipping down the slide, all by himself.

The mother of two says she likes this particular playground because it is specially designed for Sam's age group. She can let him explore and tackle each new apparatus on his own.

"I try not to hover," she said. "I think it's important for him to fall once or twice; he needs to figure out his own limits."

Meanwhile, it's becoming clear that playgrounds are not what they used to be. Towns and schools across the country have been bulldozing the old metal on concrete playgrounds in exchange for softer surfaces, lower platforms and fewer moving parts. The emphasis on safe play zones for children has never been greater. But some question whether these changes are making a difference when it comes to injured kids.

The Consumer Product Safety Commission (CPSC) estimates that 2008 saw just over 220,000 ER visits from kids injured on playgrounds. This actually reflects a small increase from their 1999 estimate of 205,000.

The most common playground injuries requiring medical attention were fractures, bruises, cuts and sprains, which made up 85 percent of all visits. Ninety five percent of children taken to the ER after a playground injury were treated and released.

And some parents may be surprised to learn that their efforts to keep their kids safer on the playground may actually be causing more injuries than they prevent.

A 2009 study out of Winthrop University Hospital in Mineola, N.Y., found that 14 percent of fractures to one of the lower leg bones, called the tibia, occurred on slides. Surprisingly, 100 percent of them happened in children who were riding down the slide on the lap of a parent. No children who slid alone sustained the injury.

The researcher, Dr. John T. Gaffney, chief of pediatric orthopedic surgery says he did this study after seeing children come into the ER one after another with a similar history and diagnosis.

"The parents were very frustrated and upset to learn that they had inadvertently contributed to their child's fracture when they thought they were helping," says Gaffney.

Some experts say cuts and scrapes, and even the broken bones will heal, but a playground's effect on a child's emotional development may be long-lasting. There are a number of critics of these new super-safe play areas.

Ellen Sandseter and colleagues from Queen Maud University College of Early Childhood Education in Trondheim, Norway, wrote about the effects of "safe" playgrounds and overly cautious parents on child development in a 2011 article in Evolutionary Psychology.

According to the article, a young child naturally fears the highest bar of the jungle gym or that extra twisty slide. These fears are adaptive, meaning they have a purpose, preventing them from being injured.

Taking Risks on Playground Usually Good for Kids

Risky play is the process by which children slowly confront these fears as their maturity and physical skill level advances. Upon conquering the new feat, the child is left with an exciting, positive feeling which replaces their former fears. When a child's playground consists of only supersafe play areas or if their parent is overprotective, they do not get to experience these small victories -- and that may ultimately leave them with anxiety that is inappropriate for their age and physical skill level.

"Playgrounds are, in many ways, a microcosm of a child's world," says Mark A. Reinecke, chair of psychology and child development at Northwestern University in Illinois. "The lessons learned there reverberate through their lives."

He says a child can come away from play with very different impressions based on what kind of experience they are allowed to have. "I have the capacity to master my world, a sense of efficacy and competence or, conversely, that I can't manage it."

And when parents are overly concerned with safety, the child will usually pick up on it and they may even become afraid of the playground.

"If the parent appears anxious or fearful, the child will attend to these cues and respond accordingly," says Reinecke.

Imagination, creativity and the ability to get along with others are also traits that form during play time away from adults.

"We know that children need some unsupervised time outdoors to develop their own capacities for make-believe play, and cooperation with their peers," says Dr. Jacqueline Olds, associate clinical professor of psychiatry at Harvard Medical School in Boston, Mass. "All of this is interfered with when the parents feel that there must be an adult scrutinizing at all times."

When Should We Intervene in Play?

Dr. Gary Smith, director of the Center for Injury Research and Policy at Nationwide Children's Hospital in Columbus, Ohio, says there is no need to choose between a stimulating playground and a safe one.

He says that most playground injuries -- 67 percent of them to be exact, according to the CPSC report -- are from falls. So interventions should focus on limiting heights and adding soft surfaces for landing.

"We know that they will eventually fail when they try to reach a little further or jump a little higher," says Smith. "Failure is normal and children should learn to develop resilience. However, they should not have to pay the price of a broken bone or traumatic brain injury when they fail."

But before you go measuring how high your monkey bars reach, experts say, finding the right balance between supervision and freedom is the ultimate goal.

"All parents want to protect their child, physically and emotionally," says Reinecke. "This needs to be balanced with providing the child with a secure base, a sense that they can explore their world with confidence, knowing that a parent or caregiver is there if needed."